Aptitude - Profit and Loss - Discussion

gain=s.p-c.p.
let the c.p be 'x' and s.p be 'y'.
profit is=(y-x)
condntn is if s.p is doubled then only profit will be tripled.

3*profit=(s.p-c.p)
3(y-x)=(2y-x)
y=2x;

I am explaining the question in accordance with CP=x and SP=y.

The real confusion in this question is that in the statement they have said "selling price is doubled", which means the equation should be 2y = 3(y-x).

But this is wrong, because on left side we are taking only NEW SP but the right side the equation is in terms of Profit.
Remember they have given the relation if SP and Profit in proportionality and NOT EQUAL.

But, we have to make an equation in terms of profit on both sides. So, to get the new Profit, the SP is doubled and the original CP is subtracted from the same i.e. 2y and then subtract the CP from it which gives the equation as : (2y-x) .

I hope the rest is clear to all .. the same is very well explained by @atul

Thank you.

Can you explain me if selling price is doubled then how profit is thrice the cost price.

As we all know that
selling price=cost price+ profit. I am little bit confused.

Guneet thanks I got it clearly !

How can you write profit=3(y-x)=2y-x ? Please can any one tell me.

@Pratyusha

Refer balaji's explaination..very clear. No body can explain more than him.

Well done balaji!

Ya..balaji's explanation is clear Profit= y-x___________(1)

From the data given, if selling price doubles, profit will be tribled. So that

From(1), we can write

Profit = y-x, here from the data given if y doubles profit will be tribled. so we can write in place of profit we can write y-x

3(y-x) = 2y-x.

PROFIT = 3(Y-X)= (2Y-X)
= 3Y-3X-2Y+X
= 1Y-2X
(i.e)Y=2X : Profit = (Y-X)(i.e) =(2x-x)=Rs.x
Profit% = C.P/profitX100= X/X*100=100%.
FROM HERE EXPLAIN CLEARLY.

See balaji explaination. Its very clear.

Let Cost Price Be X AND Selling Price be Y And Profit for this is Z, THEN BY given Condition
((y-x)/x)*100=Z -------------- (1)

Similarly By Given Condition
((2y-x)/x)*100 =3Z Or Z = ((2Y-X)/3X)*100 -------- (2)

Both eqn 1 and 2 are equal equating these two eqn gives
3(y-x) =2y-x
y=2x

Put this value in eqn 1 and get z = 100.